# Analysis of Scattering from Archival Pulsar Data using a CLEAN-based Method

## TL;DR

This study applied a CLEAN-based method to archived pulsar data to measure scatter times and their frequency dependence, revealing that scattering effects are often negligible but can be significant at low frequencies, with results consistent with a Kolmogorov turbulence spectrum.

## Contribution

The paper introduces a CLEAN-based approach for measuring scatter times from archival pulsar data and estimates the frequency scaling index assuming Kolmogorov turbulence.

## Key findings

- Scatter time frequency index $eta$ close to -4.4 for Kolmogorov turbulence
- Most pulsars show negligible scattering effects at higher frequencies
- Significant scattering observed at lowest frequencies for 21 pulsars

## Abstract

In this work we adopted a CLEAN-based method to determine the scatter time, $\tau$, from archived pulsar profiles under both the thin screen and uniform medium scattering models and to calculate the scatter time frequency scale index $\alpha$ where $\tau\propto\nu^{\alpha}$. The value of $\alpha$ is $-4.4$, if a Kolmogorov spectrum of the interstellar medium turbulence is assumed. We deconvolved 1342 profiles from 347 pulsars over a broad range of frequencies and dispersion measures. In our survey, in the majority of cases the scattering effect was not significant compared to pulse profile widths. For a subset of 21 pulsars scattering at the lowest frequencies was large enough to be measured. Because reliable scatter time measurements were determined only for the lowest frequency, we were limited to using upper limits on scatter times at higher frequencies for the purpose of our scatter time frequency slope estimation. We scaled the deconvolved scatter time to 1~GHz assuming $\alpha=-4.4$ and considered our results in the context of other observations which yielded a broad relation between scatter time and dispersion measure.